Improvements in telegraphic apparatus



of Fig. 2. Fig. 4 represents a modification in net and also its action on they armature without the armature and to increase it-s'capacity to .sists, first, in constructing the core of the helixaround and in'close proximity to its outer surface, with'the poles of the magnetin close proxing around its outer surface; second, in arrangincreased; fourth, in constructing the helix of UNITED STATES PATENT OFFICE.

L. BRADLEY, or E YORK, v. Y.

IMPROVEMENTS IN TELEGRAPH I CjA PPAR'ATUS.

Specification forming part of LettersPatent No. 29,761, dated August 28, 1860,

To all whom-may concern:

Be it known that I, L..BRADLEY, of the city, county, and State of New York, have invented certain new and useful Improvements in Electro-Magnets, .of which the following is a full, clear,' andexact-description, reference being had to the accompanying drawings, forming part ofithis specification, in which Figure 1 represents a perspective view of an electro-magnet embracing my improvements. Fig. 2 represents a plan of the magnet. Fig. 3 represents a vertical section on the line as w the arrangement of the legs of the-magnet and armature. Y

The objects of my improvements in electromagnets are, to increase the power of the magincreasing the quantity of helical wire; togive greater freedom and ease to the movement of make a greater number of contacts in a given time; and, also, to arrange the helix so as to increase or diminish the power-of the magnet as required and to give greater distinctness to the sound produced by the strikes of the armature in its vibrations.

My invention for efi'ecting these objects conso as to pass through the center of the coil,

imity to each other on the outside of the coil, by which means a more powerful and active magnet is produced with a less coil than in the old construction, in which the magnet only passes through the center of the coil without extenda mag'netinconcentric sections, with .conductors connecting one section with another throughout, in connection with a double switch arranged to form a'direct connection between any two sections'of the helix, so that'oue ormore sections may be passed over and discon nected; from the. circuit when required to di minish the power of the magnet and the resistance to the electric current passing through the helix; fifth, in the application of tensionstrings in connection with a soundingboard,- electro-magnet, and armature, against which the armature strikes, rendering the sound more distinct; sixth, in arranging the armature be: tween the poles of the magnet with its center of motion also between the poles and near the center of its length, by whichmeans'the-ease and rapidity of its movements are increased and firmer contacts are. made. Q p I In the accompanying drawings is represented an eleetro-magnet embracing my improvement's, which consists of a bed-plate, A, to support the diii'erent parts. From opposite sides of the bed-plate rise two side pieces, B, con nected together by a cap, (3, on which rests an 'electro-magnet, D, and beneath the cap,-s'upported on the bed-plate byfeet a, is a soundingboard, E.

The magnet consists of a helix composed of a series of concentric sections, b b, of insulated wire, through the center of which passes a core or magnet, F, of soft iron, which extends across the ends and over the outer surface of the helix and in close proximity to it, while the ends.

or poles of the magnet are also brought in near. proximity to each other; The concentric sections of insulated wire are connected with each other through projecting knobs d, which extend through and a short distance above-a non-conducting cap, 6, covering the end of the helix. Pivoted to this cap is a double switch, f, consisting of two arms which are jointed to eachother, and so arranged as tobe-brought in contact with the. different knobs connecting the several sections of the helix, so that a direct connection may be made between any two sections composing the helix and the intermediate ones passed over.

The magnet is placed in an upright position and suspended from itsupper leg by means of thin metallic spring g, is a pendent armature, G, which is arranged in close proximity to the outer surface of the helix and alsoto the logs of the magnet. 1 r e Attached to the lower endot the armature, I

which extends below the helix, is an adjustable fork, h, for regulating the length ot the vibrations of the armature in closing or breaking the circuit. These forks vibrate between two sounding-wires, i it, placed at a proper distanco apart and firmly confined at one end to the bed-plate or end ofthe sounding-board, and pass over the top of the sounding-board andrest on a bridge, H, just back of the fork of the armature, and are confined at the opposite end to the bed-plate or sounding-board by thumb-screws I, so that their tension may be regulated. I

To one side of the armature is attached one end of a retracting-spring, m, for withdrawing the armature from the magnet and the sounding-wire on that side, and to the other side is attached one end of a counter-spring, n',which acts in an opposite direction to that of the retracting spring. The other ends of these springs are connected by cords with adj ustin gpins 0, by which thetension of the springs is mutually adjusted to each other.

The armature, instead of being arranged, as represented in Fig. 1, parallel to and on the same side of both the legs of the magnet, may be arranged parallel to the legs and pass between them, as shown in Fig. 4, the legs being turnedso thet -the distance between them is sufficient to admit the armature to be placed between and parallel to them, in which case the armature, instead of being suspended at the end, is suspended to vibrate on a center between the two poles of the magnet and near its own center.

The soundin g-b'oard E i n present instance is made in the form of a rectangular box, 'but any other form may be given it that is thought best.

In arranging this electro-magnet for use the retracting and counter springs acting upon the armature are adjusted so as to place the retracting-spring in a higher state of tension than the counter-sping, and the fork attached to the end of the armature is also adjusted be-- tween the wires to regulate the length of the vibration of the armature in closing and breaking the circuit. The switch-bar is also ad. justed so that the current will pass through a greater or less number of sections composing the helix, as may be required to operate the armature, depending upon the length of the main line in connection.

This magnet, in tclcgraphing, can be used either as a sounder to receive and communicate intelligence by sound alone or as a relaymagnet operating a local circuit. \Vh'en used for the former purpose the wires of the main circuit are connected with it in the usual manner, and the impulses of 'the electric current from the circuit cause the armature to vibrate,

striking the sounding-wires-oneither side, andthe sound of its'beats through the medium of the wires and the sounding-board is intensified, so that the lightest touch is heard with great distinctness, by which means the communication of intelligence with this mechans the single spring.

ism is rendered clear and distinct by sound alone without the useof a local circuit. /Vhen this magnet is used as a relay the local circuit may be connected with one of the soundingwires and the magnet in the usual manner by means of screw-cups. v

' In constructing the magnet so that itnot only passes through the center of the helix but extends around the end andover the outer surface, bringing the two poles in close proximity, I have found from repeated experiments that with a much less quantity of wire a more powerful magnet is obtained than in the old mode, in which the magnet only passes through ized quicker' and more freely than in the old mode, and which is absolutely necessary in order to communicate intelligence with great rapidity.

In arranging two springs acting in opposite directions on the armature, one of which is placed in a greater state of tension than the other, a more rapid vibration of the armature is obtained than by the use of a single spring, owing to the fact that springs in a high state of tension vibrate more rapidly than in a'low state, and which this arrangement admits of without increasing the power required to operate the armature, as the increased power ex erted by the spring in a high state of tension is counteracted bythe opposite spring; and, moreover, by this arrangement firmer connections are made in closing the circuit than with In arrangingthe helix in concentric sections so that one or more of these sections may be thrown out by means of the switch, which, on being placed on the knobs, the current follows as the line of least resistance instead of pass- ,ing through the intermediate sections, the

power of the magnet may be increased or diminished with great facility and instantaneously adapted to long or short circuits, and

thus relieve the line of all unnecessary resistance.

I do not confine myself to the precise construction, form, or arrangement of the parts as described, as these, may be yaried without departing from the spirit of my invention. The springs operating the armature may be varied in form, construction, and arrangement,

provided they act in opposite directions on each. other, so that one may be placed in a higher state of tension than the other to in,

crease its velocity of vibrating, while its dynamic force is counteracted by the other, and instead of acting directly on the armature they may be made to act on the armature-1e- -ver used in ordinary machines. The number of sectional coils composing the helix may be increased or diminished as circumstances may require in constructing different-sized mag- I nets. The armature, when suspended so as to vibrate on its center, may be arranged-either in an upright or horizontal position, and when used with the horseshoe-magnet and helix, 'instead of vibrating in a plane parallel to'the legs, may vibrate on a center between the legs and in aplane perpendicular to the side of the magnet. Having thus described my improvements in electro-magnetic machine, what I claim therein as new, and desire to secure by Letters Patent is-- 1: The combination of a helix with a core arranged to pass through its center and around andin close proximity to its surface with the poles, also in near proximity .to each other, for

the purpose set forth.

2. The combination of a'magnetconstructed substantially as described with a keeper ar-' ranged parallel to the legs of the magnet and, in close proximity to the periphery of the helix, for the purpose set forth.

- 3. The combination of the armature or its equivalent for breaking and closing the circuit with two springs arranged to act on each other in opposite directions, for the purpose set forth.

L. BRADLEY.

Witnesses:

F. S. SMITH, JOHN S. HOLLINGSHEAD. 

